Student Kelsey Friend recounted to ABC News' George Stephanopoulos how Beigel unlocked the door of his classroom to give refuge to her and other students as they fled. They hid behind his desk. As he went to relock the door, the shooter walked past and fatally shot him.

Students Kelsey Friend (left) and David Hogg recount their stories about yesterday's mass shooting at the Marjory Stoneman Douglas High School where 17 people were killed. Mark Wilson/Getty Images

"I am alive today because of him," Friend said when given the opportunity to address Beigel's family. "Thank you for bringing and having this amazing person in life and giving him the power to be stronger than I could have ever been."

Beigel's impact will never be forgotten by those he saved.

"He will be missed by me and multiple friends, his name with me will live on," Friend said.